Bleached Sugarcane Bagasse Research Articles

Magnetic paper from sugarcane bagasse fibers modified with cobalt ferrite nanoparticles

Magnetic paper sheets were prepared from bleached sugarcane bagasse fibers and cobalt ferrite nanoparticles by lumen loading method. Sugarcane bagasse is an important fibrous raw material widely used worldwide for papermaking, whereas cobalt ferrite nanoparticles is an appropriate material for fibers modification given their magnetic properties. Cobalt ferrite nanoparticles were synthetized by coprecipitation method and coated with silica by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) molecules. Then, silica coated magnetic nanoparticles were functionalized with polyethylenimine (PEI), as retention aid, by electrostatic bonding. It was observed that the loading degree of magnetic fibers depends on nanoparticles concentration and PEI dosage, which was determined by thermogravimetric analysis (TGA). Scanning electron microscope (SEM) shows the deposition of coated nanoparticles on the surface and into macropores of fibers. All samples exhibited ferromagnetic behavior. The coercivity values of magnetic fibers are higher than 0.2 kOe. This indicates that these fibers could be used to produce paper for magnetic recording purposes. Magnetic papers with 10 and 20% of modified fibers were manufactured. Brightness and tensile index of papers were decreased with the rise of loading degree. CIEL*a*b analysis shows the color differences between unmodified and modified papers.

Preparation and Characterization of Nanocomposite Films Containing Nano-Aluminum Nitride and Cellulose Nanofibrils.

Nanocomposites consisting of cellulose nanofibrils (CNFs) and nano-aluminum nitride (AlN) were prepared using a simple vacuum-assisted filtration process. Bleached sugarcane bagasse pulp was treated with potassium hydroxide and sodium chlorite, and was subsequently ultra-finely ground and homogenized to obtain CNFs. Film nanocomposites were prepared by mixing CNFs with various AlN amounts (0–20 wt.%). X-ray diffraction revealed that the crystal form of CNF-AlN nanocomposites was different to those of pure CNFs and AlN. The mechanical performance and thermal stability of the CNF-AlN nanocomposites were evaluated through mechanical tests and thermogravimetric analysis, respectively. The results showed that the CNF-AlN nanocomposites exhibited excellent mechanical and thermal stability, and represented a green renewable substrate material. This type of nanocomposite could present great potential for replacing traditional polymer substrates, and could provide creative opportunities for designing and fabricating high-performance portable electronics in the near future.

Investigation of deposit problem during sugarcane bagasse pulp molded tableware production

Abstract Formation of brown deposit is quite a common problem in hot pressing stage of cellulosic pulp molded tableware production, especially using bleached sugarcane bagasse pulp as raw material which blocks the pipes, corrodes and damages the equipment, increases the cleaning frequency and correspondingly increases the costs as well as reduces the quality of the products. In this work, the composition of the deposit was analyzed, and the effects of fines to the drainage and drying process of cellulosic pulp molded tableware production was studied by thermogravimetric analysis to investigate the cause of this problem. It was found that high contents of fines containing waterproofing agent and oilproofing agent was the main cause of this problem. Compared to the pulps without fines, pulp composed of 100% fines had lower absolute value of zeta-potential and higher adsorption ability of waterproofing agent and oilproofing agent. Besides, fines could increase the water retention capacity and prolong drainage time of pulp, which would result in higher drying intensity and generated strong vapor during drying. During hot pressing process of cellulosic pulp molded tableware production, the strong vapor could bring the small and light fines containing waterproofing agent and oilproofing agent into the air vents and the deposit was formed. The finding of this work would give supports for cleaner production of cellulosic pulp molded tableware by understanding the mechanisms of deposit formation which would be helpful to reduce the deposit problem to some extent.

Cellulose nanocrystal‐based poly(butylene adipate‐co‐terephthalate) nanocomposites covered with antimicrobial silver thin films

In this study, we reported the preparation and prospective application of the nanocomposites of poly(butylene adipate‐co‐terephthalate) (PBAT) reinforced with cellulose nanocrystals (CNCs). CNCs were isolated from bleached sugarcane bagasse by acid hydrolysis and functionalized with adipic acid. Nanocomposites were prepared with different concentration of CNCs (0.8, 1.5, and 2.3 wt% CNC) by solution‐casting method and then were covered with silver thin film by magnetron sputtering. The results showed that the surface modification increased the degree of crystallinity of nanocrystals from 51% to 56%, decreasing their length and diameter. Moreover, AFM‐IR spectroscopy revealed that the modified CNCs were covered by adipic acid molecules, improving the dispersion of nanocrystals in PBAT. Well‐dispersed modified CNCs acted as heterogeneous nuclei for crystallization of PBAT, and increased the storage modulus of the polymer by more than 200%. These improvements in thermal and mechanical properties of CNC‐based PBAT associated with the decrease of 56% in the Escherichia coli biofilm formation on nanocomposites (antibacterial properties) qualify the CNC/PBAT nanocomposites covered with silver thin films to be used as food packaging. POLYM. ENG. SCI., 59:E356–E365, 2019. © 2019 Society of Plastics Engineers

Effects of physical and chemical structures of bacterial cellulose on its enhancement to paper physical properties

Bacterial cellulose (BC) was used to reinforce paper sheets made from non-woody fibers, e.g. sugarcane bagasse. BC produced from static and agitated fermentation methods was mixed with bleached sugarcane bagasse pulp (BSBP) to produce composite paper sheets. BC from static culture had a higher degree of polymerization, crystallinity, and crystallite width. Adding BC at a low ratio (<1% of the dry weight of the sheets) can effectively improve the mechanical properties of BSBP paper sheets. Adding static BC improved the tensile index of BC-BSBP composite sheets up to 25%. Furthermore, BC was also chemically modified or cationized by reacting with (3-chloro-2-hydroxypropyl)trimethylammonium chloride. The results demonstrated that the cationization reaction had to be maintained at a low level (DS < 0.005) for effective improvement in mechanical properties of the BC-BSBP composite sheets. The improvements in tensile index were up to 10 and 32%, compared to the unmodified BC-reinforced sheets and sheets without BC, respectively. The low addition and low cationization levels suggest an economical prospect for static BC being used in the paper-based material industries to improve the qualities of non-woody fiber products.

Viscoelastic Properties of Pulp Suspensions of Bleached Sugarcane Bagasse: Effects of Consistency and Temperature

The viscoelasticity of pulp suspensions of bleached sugarcane bagasse was studied in a stress/shear rate-controlled rheometer using concentric cylinders geometry. Results for the elastic (G') and viscous (G'') modulus, as well as complex viscosity (n*), are presented as a function of the suspension consistency (1.0 wt% ≤ Cm ≤ 6.0 wt%) and temperature (20, 40, and 60 °C). The results show an effect of the concentration and temperature on the viscoelastic moduli and cross-over point. A power law model was fitted to the experimental results for elastic modulus, It was found that the complex viscosity exhibited shear-thinning behavior for all the suspensions. Only the pulp concentration had an influence on this material function.

Production of cellulose nanocrystals from sugarcane bagasse fibers and pith

Cellulose nanocrystals (CNs) were produced from unbleached and bleached sugarcane bagasse pulps by classical H2SO4 hydrolysis of fiber and pith fractions of pressed culms. Both the raw materials and final products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, field emission gun scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The advantages and disadvantages of using both unbleached and bleached pulps for the production of CNs were demonstrated and discussed.

Extraction and comparison of carboxylated cellulose nanocrystals from bleached sugarcane bagasse pulp using two different oxidation methods

Two kinds of carboxylated cellulose nanocrystals (CCNs) were prepared by using ultrasonic assisted 2,2,6,6-tetramethylpiperidinyl-1-oxy radical (TEMPO) mediated oxidation and one-step ammonium persulfate (APS) oxidation, which were denoted as TEMPO-oxidized CCNs (TO-CCNs) and APS-oxidized CCNs (AO-CCNs), respectively. The effects of oxidant content on the yield, carboxyl content, degree of polymerization (DPv) and morphology of the oxidized celluloses in the two oxidation methods were studied. Furthermore, the chemical structure, crystallinity and thermal stability of TO-CCNs and AO-CCNs were evaluated and compared by Fourier transformed infrared spectra, X-ray diffraction and thermogravimetric analyses. The results showed that with increase of oxidant content in the two methods, the carboxyl groups on the surfaces of TO-CCNs and AO-CCNs were both improved. And a remarkable decline of the DPv of cellulose sample also appeared in the two oxidative treatments. In addition, AO-CCNs exhibited a higher crystallinity and an enhanced thermal stability compared with TO-CCNs.

Rheology of pulp suspensions of bleached sugarcane bagasse: Effect of consistency and temperature

Rheological properties, such as yield stress and apparent viscosity, of pulp suspensions of bleached sugarcane bagasse were studied in a stress-shear rate controlled rheometer using concentric cylinders geometry. Results were statistically analyzed and presented as a function of the suspension consistency (0.5% ≤ Cm ≤ 4.0%) and temperature (20°C, 40°C, and 60°C). The yield stress was influenced by the consistency and temperature. The apparent viscosity was influenced only by the consistency. A power law model was fitted to the experimental results of yield stress. In flow tests, all the suspensions showed shear-thinning behavior, which was in agreement with the Carreau-Yasuda model.

Construction of individual, fused, and co-expressed proteins of endoglucanase and β-glucosidase for hydrolyzing sugarcane bagasse

At least a combination of endoglucanase (EglII) and β-glucosidase (BglZ) is required for hydrolyzing crystalline cellulose. To understand the catalytic efficiency of combination enzymes for converting biomass to sugars, EglII and BglZ were constructed in the form of individual, fused as well as co-expression proteins, and their activities for hydrolyzing sugarcane bagasse were evaluated. The genes, eglII isolated from Bacillus amyloliquefaciens PSM3.1 earlier and bglZ from B. amyloliquefaciens ABBD, were expressed extracellularly in Bacillus megaterium MS941. EglII exhibited both exoglucanase and endoglucanase activities, and BglZ belonging to the glycoside hydrolase 1 family (GH 1) showed β-glucosidase activity. A combination of EglII and BglZ showed activity on substrates Avicel, CMC and sugarcane bagasse. Specifically for hydrolyzing sugarcane bagasse, fused protein (fus-EglII+BglZ), co-expression protein (coex-BglZ+EglII), and mixed-individual protein (mix-EglII+BglZ) produced cellobiose as the main product, along with a small amount of glucose. The amount of reducing sugars released from the hydrolyzing bleached sugarcane bagasse (BSB) using fus-EglII+BglZ and mix-EglII+BglZ was 2.7- and 4.2-fold higher, respectively, than steamed sugarcane bagasse (SSB), indicating the synergetic enzymes worked better on treated sugarcane bagasse. Compared with fus-EglII+BglZ and mix-EglII+BglZ, coex-BglZ+EglII released more mol reducing sugars from SSB, indicating the enzymes were potential for biomass conversion. Additionally, coex-BglZ+EglII acted on BSB 2.5-fold faster than fus-EglII+BglZ. Thus, coex-bglZ+eglII expression system was the best choice to produce enzymes for hydrolyzing sugarcane baggase.

Mechanical properties of HIPS/sugarcane bagasse fiber composites after accelerated weathering

The effect of accelerated weathering on the visual appearance and on mechanical properties of high impact polystyrene (HIPS) as well as HIPS reinforced with mercerized and bleached sugarcane bagasse fibers composites are investigated. After accelerated weathering period of 900h, under UV-B radiation and moisture regular cycles, changes in mechanical properties are investigated by tensile tests. Materials fracture surfaces are investigated by scanning electron microscopy (SEM). The study showed that the exposure time was sufficient to change the visual appearance of HIPS as the composites. From this study, it was observed that composites reinforced with bleached fibers are less susceptible to accelerated weathering exposure than composites reinforced with mercerized fibers, which is explained by the higher amount of lignin present in mercerized fibers.